In recent years, spam has become a major problem for all Internet users. As the cost of processing power, email address acquisition and email software continue to fall, spam becomes increasingly cost-effective for spammers. Given the negligible cost involved in sending millions of unsolicited email messages, spammers need only capture a small response rate to make a profit. The growth trend of spam shows no sign of abating. According to recent statistics, spam currently accounts for over half of all email traffic in the U.S. This increase in both the volume and percentage of spam is not only worsening a resource drain for IT, it is also affecting how end users view email, which has become the primary form of communication in the enterprise.
Presently, there are products for filtering out unwanted email messages. However, these products typically fail to effectively compensate for the escalating volumes of spam.